Cooler

ABSTRACT

A cooler includes a base plate, fins, a coolant discharge passageway, and a coolant supply passageway. The coolant supply passageway includes a supply passageway partition that divides the coolant supply passageway into a plurality of divided supply passageways. The supply passageway partition extends in a coolant flowing direction within the coolant supply passageway. A first coolant supply port supplies the coolant to a first divided supply passageway that is at least one of the divided supply passageways, from one side along the base plate. A second coolant supply port supplies the coolant to a second divided supply passageway that is at least one of the divided supply passageways, from another side along the base plate. Coolant nozzles jet the coolant toward the fins. The coolant nozzles include a coolant nozzle communicating with the first divided supply passageway and a coolant nozzle communicating with the second divided supply passageway.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2013-060727 filed on Mar. 22, 2013 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a cooler. More particularly, the invention relates to an impinging jet type cooler in which a cooling object, such as a semiconductor chip, is attached to one surface of a base plate, and a coolant is caused to impinge upon the other surface of the base plate.

2. Description of Related Art

A type of cooler for cooling a semiconductor chip or an electronic component part is known in which a cooling object, such as a semiconductor chip, is attached to one surface of a base plate of the cooler, and a coolant is jetted toward the other surface of the base plate, that is, the opposite surface thereof to the one surface. This type of cooler, in which the jetted coolant is caused to impinge on the other surface of the base plate, is sometimes called impinging jet type cooler. In this specification, the site where a cooling object, such as a semiconductor chip, is attached is referred to as “base plate”. Furthermore, for the sake of convenience in description, the surface to which a cooling object is attached, that is, the “one surface”, is referred to as the obverse surface of the base plate, and the opposite surface to the “one surface”, which is the “other surface”, is referred to as the reverse surface.

An example of the impinging jet type cooler is described in, for example, Japanese Patent Application Publication No. 2011-166113 (JP 2011-166113 A). In the cooler described in JP 2011-166113 A, a side wall of the housing corresponds to a base plate. The cooler has a partition plate that is disposed so as to face the reverse surface of the base plate, and that divides a space inside the housing into a space that faces the base plate and a space that is apart from the base plate. A coolant is supplied from outside into the space that is part from the reverse surface of the base plate. That is, this space itself forms a coolant supply passageway. Incidentally, an opening formed in the housing so as to supply the coolant to the base plate is referred to as a coolant supply port. There is provided a coolant nozzle that jets the coolant from the partition plate toward the reverse surface of the base plate. The coolant nozzle has an opening that is elongated from a side closer to the coolant supply port to a side remote from the coolant supply port. Alternatively, the cooler has a plurality of coolant nozzles that are spotted side by side from the side near the coolant supply port to the side remote from the coolant supply port. Of the spaces divided by the partition plate, the space that faces the base plate is provided with a coolant discharge opening that is formed in a wall surface of the housing. The coolant discharge opening is formed in one of the side walls of the housing which faces the side wall that is provided with the coolant supply port. The coolant jetted from the coolant nozzle impinges upon the reverse surface of the base plate, and then flows toward the discharge opening. That is, a space between the partition plate and the base plate forms a coolant discharge passageway. Incidentally, in the cooler described in JP 2011-166113 A, the reverse surface of the base plate is provided with a plurality of fins.

Furthermore, another example of the impinging jet type cooler is described in, for example, Japanese Patent Application Publication No. 5-3274 (JP 5-3274 A). In this cooler, partition members for separating semiconductor elements arranged on a substrate are provided so as to form semiconductor element-cooling chambers. Coolant nozzles are attached to the element-cooling chambers via cooling medium supply members that cool the cooling medium, and each element is independently cooled, so that temperature differences among the elements are made small.

SUMMARY OF THE INVENTION

The coolant nozzle has an opening that is elongated in the flowing direction of the coolant. Alternatively, the cooler has a plurality of coolant nozzles that are spotted in the flowing direction. Then, via the coolant nozzle or nozzles, the coolant moves from the coolant supply passageway to the coolant discharge passageway. Therefore, in the coolant supply passageway, the coolant flow rate decreases from the upstream side to the downstream side whereas in the coolant discharge passageway, the coolant flow rate increases from the upstream side to the downstream side.

In the cooler disclosed in JP 2011-166113 A, the partition plate is parallel to the base plate, and the flow path cross-sectional area of each of the coolant supply passageway and the coolant discharge passageway, that is, the flow path area on the cross section of each passageway orthogonal to the flowing direction of the coolant, is constant in the coolant flowing direction. In the coolant supply passageway, since the flow rate decreases from the upstream side to the downstream side and the flow path cross-sectional area is constant, the pressure of the coolant decreases downstream. In the coolant discharge passageway, since the flow rate increases from the upstream side to the downstream side and the flow path cross-sectional area is constant, the pressure of the coolant increases downstream. If the distribution of pressure within each of the coolant supply passageway and the coolant discharge passageway is non-uniform in the flowing direction of the coolant, the pressure or flow speed of the coolant caused to impinge on the base plate becomes non-uniform, so that the cooling capacities for the cooling objects attached to the base plate are non-uniform.

In the case where cooling chambers are separated for each element as in the technology described in JP 5-3274 A, the distribution of pressure is also non-uniform in the flowing direction of the coolant, similarly to the case described in JP 2011-166113 A, since the pressure of the coolant decreases at the downstream side of the coolant supply passageway or increases at the downstream side of the coolant discharge passageway.

The invention provides an impinging jet type cooler capable of uniformly cooling a cooling object,

A cooler in accordance with an aspect of the invention includes:

a base plate configured to allow a cooling object to be attached to one surface of the base plate;

a fin attached to an opposite surface of the base plate to the one surface, the fin including a plurality of fins that are arranged parallel to each other so that flat surfaces of the fins face each other;

a coolant discharge passageway communicating with a space defined between the plurality of fins and provided adjacent to the fins;

a coolant supply passageway provided at a side of the opposite surface of the base plate and across the coolant discharge passageway from the fins, the coolant supply passageway extending along the base plate, the coolant supply passageway including:

a supply passageway partition portion configured to divide the coolant supply passageway into a plurality of divided supply passageways, the supply passageway partition portion extending along a coolant flowing direction within the coolant supply passageway;

a first coolant supply port configured to supply the coolant to a first divided supply passageway that is at least one of the plurality of divided supply passageways, from one side along the base plate;

a second coolant supply port configured to supply the coolant to a second divided supply passageway that is at least one of the plurality of divided supply passageways, from another side along the base plate; and

a coolant nozzle configured to jet the coolant toward the fin, the coolant nozzle including the coolant nozzle communicating with the first divided supply passageway and the coolant nozzle communicating with the second divided supply passageway.

According to this construction, since the coolant supply passageway is partitioned into the first and second divided supply passageways by the supply passageway partition portion and the coolant is supplied thereto from one side and from the other side, the coolant can be caused to flow in both directions in the coolant supply passageway. The pressure of the coolant declines at the downstream side of each of the first and second divided supply passageways. However, the downstream side of the first divided supply passageway where the pressure declines is located adjacent to the upstream side of the second divided supply passageway in which the coolant flows in the direction opposite to the flowing direction of the coolant in the first divided supply passageway. Therefore, in the coolant supply passageway as a whole, the distribution of pressure of the coolant is made uniform along the extending direction of the coolant supply passageway. Therefore, the cooling object can be uniformly cooled.

Furthermore, in the cooler in accordance with the one aspect of the invention, the base plate may have, on the opposite surface, a curved surface that curves toward the coolant discharge passageway. The curved surface may be configured to guide the coolant to the coolant discharge passageway.

According to the foregoing construction, the coolant jetted from the nozzle toward the base plate is guided toward the coolant discharge passageway while curving along the curved surface. Therefore, the coolant flows smoothly between adjacent fins. Due to this, the impingement of the coolant upon the reverse surface of the base plate can be eased or the turbulence of the flow of the coolant occurring after the coolant impinges upon the reverse surface can be restrained, so that the pressure loss of the coolant can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG. 1 shows a perspective view of a cooler in accordance with an embodiment of the invention;

FIG. 2A shows a sectional view of the cooler from which a top plate of a housing of the cooler has been removed;

FIG. 2B shows a sectional view of the cooler taken along line B-B of FIG. 2A;

FIG. 2C shows a sectional view of the cooler taken along line C-C of FIG. 2A;

FIG. 3 shows an enlarged view of a portion III of the cooler shown in FIG. 2B; and

FIG. 4 shows an enlarged view of a portion IV of the cooler shown in FIG. 2C.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention will be described hereinafter with reference to the drawings. FIG. 1 is a perspective view of a cooler 2. It is to be noted that, in FIG. 1, component parts are illustrated as being partially cut away so that an internal structure of the cooler 2 can be seen. Hatching indicates the cut surfaces. Firstly, with reference to FIGS. 1, 2A, 2B and 2C, the cooler 2 will be described.

The cooler 2 is a device that cools cooling objects 92 a, 92 b and 92 c, such as semiconductor chips. The cooling objects 92 a to 92 c are attached to an obverse surface 3 a of a base plate 3, via an electrical insulation plate 91 that also serves as a heat spreader. The base plate 3 forms a side wall of a housing 7. It is to be noted herein that the “obverse surface 3 a” is an expression for the sake of convenience in distinguishing two opposite flat surfaces of the base plate 3. In this specification, of the base plate 3, one surface to which the cooling objects to be cooled by the cooler 2 are attached, that is, a surface that faces outside of the housing 7, is referred to as “obverse surface 3 a”, and the opposite surface to the one surface, that is, the surface that faces the interior side of the housing 7 of the cooler 2 is referred to as “reverse surface 3 b”. The cooler 2 passes a coolant inside the housing 7 and, particularly, the reverse surface side of the base plate 3, so as to cool the cooling objects. The coolant is preferably water or an antifreeze liquid, but may also be a gas such as air. Incidentally, although, in the drawings, the cooler 2 of this embodiment is disposed so that the base plate 3 faces downward, the base plate 3 can also be disposed so as to face upward.

A plurality of fins 4 are attached to the reverse surface 3 b of the base plate 3. The fins 4 are arranged parallel to each other, with their flat surfaces facing each other. The orientation of the fins 4 is orthogonal to the flowing direction of the coolant described later.

The housing 7 of the cooler 2 is generally a rectangular parallelepiped, and an internal space thereof excluding the fins 4 forms a flow path of the coolant. Inside the housing 7 there is provided partition plate 5 that divides the internal space into a space facing the reverse surface 3 b of the base plate 3 and a space apart from the base plate 3. This partition plate 5 is disposed in parallel with the base plate 3. Then, a coolant supply passageway 12 is formed between the partition plate 5 and the opposite side wall of the housing 7 to the base plate 3. Besides, a coolant discharge passageway 14 is formed in the space between the base plate 3 and the partition plate 5. The coolant supply passageway 12 and the coolant discharge passageway 14 will be described in detail later.

The cooler 2 has a plurality of supply passageway partition portions 21 that are disposed within the coolant supply passageway 12. The supply passageway partition portions 21 extend along the coolant flowing direction within the coolant supply passageway 12, and divide the coolant supply passageway 12 into a plurality of passageways. The coolant supply passageway 12 is separated into a first divided supply passageway 121 and second divided supply passageways 122. The first divided supply passageway 121 and the second divided supply passageways 122 are juxtaposed alternately with each other. The supply passageway partition portions 21 partition the coolant supply passageway 12 so that the divided supply passageways divided by the supply passageway partition portions 21 lie side by side in parallel with the base plate 3. Furthermore, as shown in FIG. 2A, the supply passageway partition portions 21 extend in the left-right direction in FIG. 2A, and both end portions thereof in the longitudinal direction are tightly stuck to inner surfaces of side walls of the housing 7. Furthermore, as shown in FIG. 2C, the supply passageway partition portions 21 are tightly stuck to the reverse surface of the partition plate 5, and are tightly stuck to the inner surface of a side wall of the housing 7 which faces the partition plate 5. Because the supply passageway partition portions 21 are arranged in this manner, the plurality of divisions of the coolant supply passageway 12, that is, the first divided supply passageway 121 and the second divided supply passageways 122, are formed so as not to allow the coolant to flow from one into another.

As shown in FIG. 2B, the space that is farther from the base plate 3 than the partition plate 5 is from the base plate 3, that is, the coolant supply passageway 12, is provided with a first coolant supply port 81 and second coolant supply ports 82. The space that is nearer to the base plate 3 than the partition plate 5 is to the base plate 3, that is, the coolant discharge passageway 14, is provided with coolant discharge openings 9. The first coolant supply port 81, the second coolant supply ports 82 and the coolant discharge openings 9 are provided in the two side walls of the housing 7 which face each other. Furthermore, the first divided supply passageway 121 and the second divided supply passageways 122, that is, the plurality of divisions of the coolant supply passageway 12, are provided with the first coolant supply port 81 and the second coolant supply ports 82, respectively. The first coolant supply port 81 and the second coolant supply ports 82 are formed so as to alternate with each other and so as to oppose each other in terms of the coolant flowing direction. The first coolant supply port 81 is formed for the first divided supply passageway 121, and the second coolant supply ports 82 are formed for the second divided supply passageways 122. In the example shown in FIG. 2A, the first coolant supply port 81 corresponding to the central first divided supply passageway 121 is formed in one of the left and right side walls of the housing 7, that is, the right side wall, and the second coolant supply ports 82 corresponding to the upper and lower second divided supply passageways 122 are formed in the other side wall of the housing 7, that, is the left side wall. Therefore, the first divided supply passageway 121, that is, one of the two groups of divided supply passageways, can be supplied with the coolant via one of the two sides, that is, the right side, and the other group of divided supply passageways, that is, the second divided supply passageways 122, can be supplied with the coolant via the other side, that is, the left side. Therefore, as shown by thick-line arrows in FIGS. 1 and 2A, the coolant flows from the right side to the left side in the first divided supply passageway 121, and the coolant flows from the left side to the right side in each second divided supply passageway 122. Thus, the directions in which the coolant flows in the first divided supply passageway 121 and the second divided supply passageways 122 that are disposed alternately with each other are opposite to each other. Therefore, the downstream side (or the upstream side) of the flow of the coolant in the first divided supply passageway 121 and the upstream side (or the downstream side) of the flow of the coolant in each second divided supply passageway 122 are close to each other.

Furthermore, as shown in FIG. 2B, the coolant discharge openings 9 are provided in one of the left and right side walls of the housing 7, that is, the right side wall. Therefore, in the coolant discharge openings 9, the coolant flows from left to right in the drawing.

Furthermore, coolant nozzles 6 extend from the partition plate 5 toward the base plate 3. As shown in FIG. 2A, each coolant nozzle 6 has an opening, in other words, a flow path, that is elongated along the flow of the coolant. The coolant supplied from the coolant supply ports 81, 82 passes through the coolant supply passageway 12, and passes through the coolant nozzles 6, and then moves into the coolant discharge passageways 14. Finally, the coolant is discharged via the coolant discharge openings 9. The coolant nozzles 6 include a coolant nozzle 6 that communicates with the first divided supply passageway 121, and coolant nozzles 6 that communicate with the second divided supply passageways 122.

As shown in FIG. 2C, each coolant discharge passageway 14 is formed as a groove having a square U shape in cross section, and each square U-shaped groove faces a plurality of fins 4. That is, each coolant discharge passageway 14 communicates with spaces defined between the fins 4. Furthermore, a distal end 6 a of each coolant nozzle 6 is in contact with upper ends 4 a of the fins 4.

Furthermore, the cooler 2 also includes a plurality of guide portions 31 provided on the reverse surface of the base plate 3. FIG. 3 shows an enlarged view of a portion III shown in FIG. 2B. FIG. 4 shows an enlarged view of a portion IV shown in FIG. 2C. As shown in FIGS. 3 and 4, the guide portions 31 are a structure for causing the coolant to smoothly flow, and are provided at positions that face the coolant discharge passageways 14, and have curved surfaces 32 that are curved from the reverse surface of the base plate 3 toward the coolant discharge passageways 14. The curved surfaces 32 extend from the reverse surface of the base plate 3, curving along a direction orthogonal to the flat surfaces of the fins 4, and also extends therefrom, curving along a direction parallel to the flat surfaces of the fins 4. Thus, the curved surfaces 32 are curved in both the sectional view shown in FIG. 2B and the sectional view shown in FIG. 2C. Furthermore, the curved surfaces 32 smoothly and continuously join the flat surfaces of the fins 4. In the sectional view shown in FIG. 2B, that is, a sectional view taken along the flowing direction of the coolant in the coolant supply passageway 12, the coolant jetted from a nozzle flows along one of the mutually facing surfaces of two adjacent fins 4 as shown by thick-line arrows in FIG. 3, and curves along the curved surface 32 as it approaches the base plate 3. Then, in the immediate vicinity of the base plate 3, the coolant flows in parallel with the base plate 3. After that, the coolant curves along the curved surface 32 of the other one of the mutually facing surfaces of the two adjacent fins 4, and moves toward the coolant discharge passageway 14. Thus, in a sectional view taken along the flowing direction of the coolant in the coolant supply passageway 12, the coolant impinges upon the base plate 3 and then moves away from the base plate 3 while curving along the curved surfaces 32. Therefore, the impingement of the coolant upon the reverse surface of the base plate 3 is eased, and the turbulence of the flow of the coolant is reduced.

Furthermore, as shown in FIG. 4, each guide portion 31 has a distal end portion 33 that is formed so as to protrude toward the adjacent coolant discharge passageway 14. In the sectional view shown in FIG. 2C, that is, a section of that is orthogonal to the flowing direction of the coolant in the coolant supply passageway 12, the coolant having flown into the spaces between the fins 4 from the coolant nozzles 6 impinge upon the reverse surface of the base plate 3, flows along the curved surfaces 32 of the guide portions 31, and then are guided from the distal end portions 33 of the guide portions toward the coolant discharge passageways 14, as shown by thick-line arrows in FIG. 4. Therefore, the turbulence of the flow of the coolant after the coolant impinges upon the base plate 3 can be reduced.

With reference to FIGS. 1 and 2B, the flow of the coolant in the entire cooler 2 will be described. The arrowed thick lines in FIGS. 1 and 2B show currents of the coolant. In FIG. 2B, “Fin” indicates that the coolant flows into the cooler 2, and “Font” indicates that the coolant flows out of the cooler 2. The coolant supplied from the first coolant supply port 81 flows in the first divided supply passageway 121 from the right side toward the left side in the drawings. Furthermore, the coolant supplied from the second coolant supply ports 82 flows in the second divided supply passageways 122 from the left side toward the right side. The coolant supplied into the coolant supply passageway 12, as it flows in the first divided supply passageway 121 and the second divided supply passageways 122, changes its flowing direction toward the base plate 3, via the elongated openings of the coolant nozzles 6. Then, this coolant is strongly jetted from the coolant nozzles 6 toward the reverse surface 3 b of the base plate 3. The coolant jetted toward the reverse surface 3 b of the base plate 3 flows between the fins 4, and is guided by the curved surfaces 32 of the guide portions 31, and flows from the distal end portions 33 of the guide portions 31 toward the coolant discharge passageways 14. In the coolant discharge passageways 14, the coolant flows toward the coolant discharge openings 9.

Finally, the coolant is discharged from the coolant discharge openings 9. Incidentally, coolant pipes (not shown) are connected to the coolant supply ports 81, 82 and the coolant discharge openings 9, and distal ends of those coolant pipes are connected to a tank and a pump (neither of which is shown). The coolant is sent to the cooler 2 and is recovered from the cooler 2, by using the tank, the pump and the coolant pipes.

Advantages of the cooler 2 will be described. Since the cooler 2 is provided with the coolant nozzles 6 elongated along the coolant supply passageways 12, the amount of the coolant moving into the coolant discharge passageways 14 gradually increases toward the downstream end of the coolant supply passageway 12. Therefore, the pressure of the coolant in the coolant supply passageway 12 gradually declines toward the downstream end of the coolant supply passageway 12. On the other hand, the coolant supply passageway 12 of the cooler 2 is divided by the supply passageway partition portions 21 into a plurality of divided supply passageways, that is, the first and second divided supply passageways 121 and 122, and the coolant is supplied into the first divided supply passageways 121 from one direction, and into the second divided supply passageways 122 from the opposite direction. Therefore, the coolant can be caused to flow in the coolant supply passageway in the two opposite directions. That is, the downstream side of each first divided supply passageway 121 is adjacent to the upstream side of each second divided supply passageway 122, and the downstream side of each second divided supply passageway 122 is adjacent to the upstream side of each first divided supply passageway 121. Hence, although the pressure of the coolant declines at the downstream side in each divided supply passageway, the low cooling capacity at the downstream side in one divided supply passageway can be compensated for by the coolant flowing in the upstream side in the adjacent divided supply passageways. Thus, the cooling objects can be uniformly cooled. Furthermore, since the coolant is guided toward the coolant discharge passageways 14 by the curved surfaces 32 of the guide portions 31, the coolant can smoothly flow between the adjacent fins 4. Therefore, the impingement of the coolant upon the reverse surface 3 b of the base plate 3 can be eased, and the pressure loss of the coolant can be reduced.

While one embodiment of the invention has been described above, the foregoing embodiment does not limit concrete forms or constructions of the invention. For example, the foregoing embodiment has a construction in which the first divided supply passageways 121 and the second divided supply passageways 122 are arranged alternately with each other and adjacent to each other so that the flows of the coolant from one side to the other side and the flows of the coolant from the other side to the one side alternate with each other. However, the first divided supply passageways 121 and the second divided supply passageways 122 do not necessarily need to be arranged alternately with each other. For example, a construction in which first divided supply passageways 121 and second divided supply passageways 122 alternate in units of two same-type divided supply passageways may be adopted. This construction, having the first divided supply passageways 121 in which the coolant flows toward one side and the second divided supply passageways 122 in which the coolant flows toward the other side, can uniformly cool the cooling objects. Thus, if a first divided supply passageway 121 and a second divided supply passageway 122 whose coolant flowing directions are opposite to each other are provided, the arrangement sequence of the divided supply passageways is not particularly limited.

Although the cooler 2 of the foregoing embodiment is provided with the coolant nozzles 6 each having an elongated opening along the flowing direction of the coolant supply passageway 12, the technology disclosed by this specification can also be applied to an impinging jet type cooler that has, instead of the elongated coolant nozzles 6, a plurality of coolant nozzles that are spotted in the flowing direction.

While concrete examples of the invention have been described above, it should be understood that these are merely illustrative and do not limit the scopes of the appended claims. The technologies described in the claims include various modifications and changes to the concrete examples illustrated above. The technical elements described or illustrated in the specification or the drawings can achieve their technological usefulness individually alone or in combinations of two or more of the elements, which are not limited to the combinations described in the claims as filed. Furthermore, the technologies illustrated as examples in the specification and the drawings can simultaneously achieve a plurality of objects, and mere achievement of one of the objects has technological usefulness. 

What is claimed is:
 1. A cooler comprising: a base plate configured to allow a cooling object to be attached to one surface of the base plate; a fin attached to an opposite surface of the base plate to the one surface, the fin including a plurality of fins that are arranged parallel to each other so that flat surfaces of the fins face each other; a coolant discharge passageway communicating with a space defined between the plurality of fins and provided adjacent to the fins; a coolant supply passageway provided at a side of the opposite surface of the base plate and across the coolant discharge passageway from the fins, the coolant supply passageway extending along the base plate, the coolant supply passageway comprising: a supply passageway partition portion configured to divide the coolant supply passageway into a plurality of divided supply passageways, the supply passageway partition portion extending along a coolant flowing direction within the coolant supply passageway; a first coolant supply port configured to supply the coolant to a first divided supply passageway that is at least one of the plurality of divided supply passageways, from one side along the base plate; a second coolant supply port configured to supply the coolant to a second divided supply passageway that is at least one of the plurality of divided supply passageways, from another side along the base plate; and a coolant nozzle configured to jet the coolant toward the fin, the coolant nozzle including the coolant nozzle communicating with the first divided supply passageway and the coolant nozzle communicating with the second divided supply passageway.
 2. The cooler according to claim 1, wherein the base plate has, on the opposite surface, a curved surface that curves toward the coolant discharge passageway, and the curved surface is configured to guide the coolant to the coolant discharge passageway. 